Furnace construction



- Nov. 26, 1935. R. D. FOLTZ ET AL FURNACE CONSTRUCTION Filed Nov. 18, 1951 2 Sheets-Sheet 1 Nov. 26, 1935. R. D. FOLTZ ET AL 2,022,312

FURNACE CONSTRUCTION Filed Nov. 18, 1951 2 Sheets-Sheet 2 v art 0 1767272 gy MW fwerfl o m' 27207262770 Patented Nov. 26, 1935 UNITED STATES PATENT OFFICE FURNACE CONSTRUCTION ration of Illinois Application November 18, 1931, Serial No. 575,942

12 Claims.

This invention relates to furnace construction and pertains particularly to a construction for furnace walls wherein the heat confining portion is built up of refractories, such as tiles of fire brick material or the like.

While not limited to such, the present construction finds particular utility in boiler furnaces and the like wherein the refractory wall structure forms part of the enclosure of the combustion chamber of the furnace and also part of the enclosure of the boiler and/or other heat transfer apparatus.

In such installations, the refractory wall portions which form part of the enclosure of the combustion chamber must be able to withstand very high temperatures, and the wall portions which form portions of the boiler enclosure must function effectively to prevent heat leakage, as by conduction losses through them. Since the hot combustion gases pass from the combustion chamber into the boiler chamber, the enclosing walls of said chambers must be so associated and related as to form in effect a continuous closure wall. In most types of boiler furnace installations, all or a part of the boiler enclosing wall is disposed above or at a higher elevation than the wall portions which enclose the combustion chamber, and in many installations the boiler enclosing wall must be of very considerable height.

Due to their proximity to the boilers, and other heat transfer accessories when same are employed, the boiler enclosing Walls do not have to withstand as high temperatures as are imposed upon the furnace chamber walls, but in order to give the boiler enclosing walls the necessary heat. confining characteristics, it has been a general practice to make them quite thick, building them of brick, the inner facing being of fire brick. As a consequence, they have been quite heavy, and provision for their proper support has presented an increasing problem with the steady increase in the size of boiler installations.

Another growing problem has been presented by the increasing requirements for accommodation of apparatus which is auxiliary to the boiler, For example, provision must be made in the boiler enclosing walls for the passage of headers, piping, soot blowers, and other adjuncts, arrangement of chases for the joining in of boiler headers, baffles and the like, accommodations for inspection or access doors and the like.

Due to differences in thermal expansion and contraction as between such apparatus and fittings on the one hand, and the wall on the other,

as well as for other reasons, it is quite .desirable that the wall and such apparatus be quite free of each other in so far as the imposition of weight or pressure of either upon the other is concerned. 5

A general object of the present invention is the provision of a furnace wall construction which will afford the desired flexibility, accessibility and facility of repair, and wherein the furnace chamber wall portion and the boiler 10 chamber wall portion are maintained in the desired relationship and each particularly qualified to perform its specialized function in cooperation with the other.

Another object is the provision .of a construc- 15 tion wherein the refractories of the furnace chamber wall portion and those of the boiler enclosing wall portion are supported on an external metallic frame, of simple construction, in such fashion and relationship that they are defi- 20 nitely retained in position and yet are free to accommodate themselves to thermal expansion and contraction without imposing injurious pressures on one another, the refractories being susceptible of removal from and replacement in any 25 selected portion of the wall structure without necessitating the dismantling of other portions.

Another object is the provision of an improved construction which is particularly adaptable to the accommodation of associated apparatus and 30 fittings, by virtue of which characteristic it may be utilized to advantage in conjunction with a great variety of boiler installations and the like.

Another object is the provision of a construction wherein the furnace chamber wall portions 35 and the boiler enclosing wall portions are maintained definitely in the desired relationship by an external steel framework, the arrangement being such that a substantial reduction in the weight of the structure may be effected over 40 prior constructions generally employed for similar furnace installations.

Other and further objects will be pointed out or indicated hereinafter or will be apparent to one skilled in the art upon an understanding of 45 the invention or its employment in practice.

For aid in explanation of the invention, we show in the accompanying drawings forming a part of this specification certain constructions wherein it is embodied, but it is to be understood 50 that these are presented for purpose of illustration merely, and are not to be accorded any interpretation calculated to limit the appended claims short of the true and most comprehensive scope of the invention in the art.

, parts of the boiler, economizer, and auxiliary with shelves apparatus in place;

Fig. 2 is a vertical transverse section through a portion of the wall illustrated in Fig. 1, the section being taken on approximately line 22 of Fig. 1;

Fig. 3 is a detail on a larger scale illustratng certain features of the wall construction;

Fig. 4 is a detail in the nature of an outside elevational view of a portion of a wall and serving to illustrate features of the construction;

Fig. 5 is a detail in the nature of a horizontal sectional view of a portion of a wall embodying I features of the invention;

Fig. 6 is a sectional elevational detail illustrating the arrangement of a soot blower; and

Fig. 7 is a sectional elevational detail illustrating the arrangement of an access or inspection door.

The nature of the invention will be most quickly and fully ascertained by an understanding of the illustrative embodiments herein shown, and which will now be described.

Referring first to Fig. 1, let it be understood that the reference character S designates a portion of a stoker by which fuel is fed into the furnace chamber, which is designated generally by the reference character C, in which chamber the fuel is burned. The reference character B designates generally a boiler, and the reference character E designates generally an economizer, which instrumentalities are disposed in the boiler chamber, which is indicated generally by the reference character C. It will be understood that only a few of the typical tubes of the apparatus, and only certain of their associated parts are here shown. The hot combustion gases evolved by the combustion of fuel in the combustion chamber pass from that chamber into the boiler chamber, where they flow in contact with the tubes of the boiler and other heat transfer apparatus, being guided through the various passes defined by the baffles D and finally flowing from the boiler chamber through the stack flue F. The wall shown in elevation'i'n Fig. 1 constitutes one of the side walls of the furnace, the lower portion forming a wall for the combustion chamber and the upper portion forming a wall for the boiler chamber.

In Fig. 2 this wall is shown in sectional elevation. The wall .structure comprises a plurality of upright column members ll] of I cross sectional form, which are ranged along the side of the furnace at suitable intervals, and connected by suitable transverse frame members H, the frames thus formed on the opposite side of the furnace being connected to each other by cross beams I2 disposed above the top of the furnace. On the lower portions of the column members I0, that is, on the 1 portions opposite the combustion chamber, are mounted horizontal members [4, which extend from one to another of the column members and project inwardly therefrom toward the furnace chamber. On the horizontal members I4 are supported the cast iron wall hangers l5, which project inwardly toward the furnace chamber, and which are respectively provided l5 and flanges I5 Upon the shelves 5 are mounted stacks of slotted refractories I 6 which are retained against horizontal movement off of the hangers by the engagement of the flanges 15 in their slots. This portion of the construction corresponds to the construction illustrated and described in U. S. Letters Patent to Foltz No. 1,747,822, granted February 18, 1913. The wall sections thus supported on the respective hangers l5 are disposed one above another to form the heat resistant furnace chamber wall, the superimposed sections being slightly spaced apart and the spaces filled with compressible refractory material, as at H, to form expansion joints which accommodate vertical expansion of the respective sections. An outer wall 18 is supported on the horizontal members M at a distance from the outer ends of the refractory l6, thereby alfording an intervening air space through which air may flow in contact with the outer surfaces of the refractories I6 and the exposed portions of the hangers On the portions of the column members 19 which are opposite the boiler chamber, are mounted horizontal members l9 at suitable vertically spaced locations, said members 19 extending from one to another of the columns l8 and projecting inwardly therefrom. The members I9 preferably are made of cast iron or other heat resisting metal. On the members I9 are mounted individually removable hangers 20 which project inwardly therefrom toward the furnace chamber, and are provided with shelves 253* spaced from the members 19, and upwardly extending flanges 20*. A stack of slotted refractory tiles 2| and 22 is supported on each of said hangers 20 and retained against movement horizontally off of the same by engagement of the flanges 20 in the slots of the tiles. The lowermost and uppermost tiles 2| of the stack are formed with the offset portions Zi and the lowermost tile 2! is disposed with its offset portion depending downwardly, so that it extends across the inner margin of the shelf 2!] and to some distance below that shelf. The uppermost tile 2| is disposed with its offset portion 2| extending upwardly. Disposed on edge and resting on the uppermost tile 2! of each stack, is a plurality of refractory tiles 24 having marginal outset portions 24 the lower of said portions being accommodated bebind the offset portions 2| of the upper tile 2|, the arrangement serving to prevent the tiles 24 being displaced inwardly from the wall. The outset portions 24 at the upper ends of the tiles 24 are likewise accommodated behind the depending offset portions 2 I of the tile 2| of the superjacent section. A suitable expansion space is left between the upper margins of the tiles 24 and the lower face of the tile 2W of the superjacent section, and this space is filled with a suitable refractory material 25 to afford an expansion joint for accommodating vertical expansion of the section below it.

The loose anchorage of the tiles 2| and 22 on the flanges 20 of the hangers permits them to move upwardly and downwardly with thermal expansion and contraction and also permits them a limited extent of horizontal movement, but prevents their being displaced outwardly or inwardly from the wall. Means is also provided for anchoring the tiles 24 against inward or outward displacement. For retaining the tiles 2 against outward displacement, yoke-like retaining members 2'. are provided of such length as to span the group of tiles 24 and having wedge-shaped arm portions engaging behind the lugs 20 of the superjacent hanger. As thus supported the retaining members 27 engage the outer sides of the tiles 2d adjacent their upper ends and serve to retain them against outward displacement from the wall. The tiles 24 .are held against inward displacement from the wall by virtue of their engagement against the offset portions 21 of the superjacent and subjacent tiles.

Refractories may be removed from any of the sections independently of other sections by removing the retaining members 21 which hold the upper tiles of the selected section, whereupon the tiles 24 may be withdrawn outwardly from the wall. When the tiles 24 of the selected section have thus been removed, the subjacent tiles of that section may be removed by sliding them upwardly off of the flanges 20 of their hanger and withdrawing them outwardly from the wall.

It will be observed that by this arrangement quite liberal spacing between the members l9 may be allowed, and also quite liberal spacing between the horizontal rows of hangers 20. Consequently, the construction aifords liberal areas, unobstructed by the metallic members, for accommodation of portions of the .boiler installation which extend through the wall. For example, it may be desirable to locate the jet tubes G of soot blowers at various positions, and provide access doors or inspection openings at various loca tions. The construction permits such features to be inserted where desired, without subjecting them or their mountings to the weight of the wall refractories. Such adjuncts may be attached to and supported by the external framework as illustrated for example in Figs. 6 and 7. Fig. 6 shows an arrangement of a soot blower, the rotary jet tube G and its connections and operating mechanism M being mounted on the external frame, the tube extending through a cast iron sleeve K which is likewise supported on the frame and extends through the wall, the wall tiles being out where necessary to afford the space for the sleeve. Fig. '7 illustrates an arrangement of an inspection door in which the cast iron housing .H is mounted on the external frame opposite an opening afforded in the wall by the omission of a requisite number of the tiles 2-4, and extends into said opening.

By virtue of the facts that the refractories are definitely anchored .in the wall and the wall is subdivided into independently supported sections of limited height, the total thickness of the furnace chamber wall portion, inclusive of its interior air space. need not exceed the usual thickness of a solid masonry wall for a similar installation, while the total thickness of the boiler chamber wall may be very substantially less. To afford the latter the desired heat confining characteristic, the refractories are covered exteriorly with a suitable lagging 28, which may be applied in plastic condition, and serves also effectively to seal the wall against air leakage. To make the offset in the wall contour occasioned by the difference in thickness between the combustion chamber wall and the boiler chamber wall, a corbelled wall section may be arranged to form the junction. This corbelled section is supported on a row of hangers 30, which are carried on the external framework as above described with respect to the other hangers, each of said hangers having a shelf 30 for supporting the tile thereon, and being provided with a series of flanges or lugs 39 arranged in progressively offset relationship from top to bottom of the hanger. The refractories are arranged in a corbelled relationship, alternate refractories being anchored to the hanger by engagement of their slots on the anchoring lugs or flanges 30 Thus the corbelled section may be arranged with its lowermost refractories in alignment with those of the combus- 5 tion chamber wall and associated therewith to form an eifective seal and expansion joint, and its upper refractories in alignment with those of the boiler enclosing wall.

Due to the comparative lightness of the boiler chamber wall, very substantial saving in the weight and size of the supporting frame members l0 may be effected, as compared with installations of commensurate size in which the usual masonry wall construction is employed for the boiler chamber wall. While in the present illustration the column members i ii are shown of uniform size from top to bottom of the furnace, such need not necessarily be the case as lighter shapes may be used for the support of the boiler chamber wall portion. It will also be understood that although .Fig. 3 shows the refractory combustion chamber wall portion and the refractory boiler chamber wall portion of like thickness, such need I not necessarily be the case in all structures embodying the invention.

What we claim is:

1. A boiler casing wall comprising an external metallic frame made up of upright members and horizontal members, hangers supported on the horizontal members and spaced laterally from the upright members and arranged in rows one above the other, refractories supported on said hangers to :form wall sections supported independently one above another in conjoining association, said sections comprising refractories lying fiatwise one upon another to form the lower portion of the section and refractories standing upright on edge to form the upper portion of the section, the refractories forming the lower portion of the section having anchoring engagement with the hangers to prevent their removal horizontally therefrom but being free for movement upwardly from the hangers, and means retaining the upright refractories against displacement inwardly or outwardly from the wall.

2. Furnace wall construction as specified in claim 1 and wherein the upright refractories are removable outwardly from the wall between the horizontal frame members upon disengagement from their retaining means.

3. A wall structure as specified in claim 1 and wherein said upright refractories have portions vertically overlapping the subjacent and superjacent anchored refractories.

4. A wall structure as specified in claim 1 and wherein the means for retaining the upstanding refractories includes a retaining member supported on a hanger of a superjacent section and depending therefrom into retentive cooperation with upright refractories of the section therebelow.

5. In furnace wall construction, in combination, a frame, wall sections supported independently one above another on the frame and spaced to one side thereof, hangers supporting the respective sections independently, and retaining members removably supported on hangers of one section and having retentive cooperation with refractories in the section therebelow.

6. A furnace wall, comprising, in combination, an external metallic frame made up of upright members, and horizontal members, a refractory combustion chamber wall portion and a refractory boiler chamber wall portion disposed in association and each made up of sections supported independently on the frame one above another and spaced laterally from the upright members of the frame, means anchoring said sections against movement toward and from the frame members but permitting them to expand upwardly, the outer surfaces of the combustion chamber wall portion being exposed for air cooling, heat insulating material applied to the outer surfaces of the boiler chamber wall portion, said combustion chamber wall portion being spaced from the upright frame members a greater distance than the boiler chamber wall portion, and a corbelled refractory wall section arranged between and in adjoining association with said wall portions, said corbelled section being supported on the frame independently of subjacent and superjacent wall portions.

7. In a boiler furnace installation having a combustion chamber and a boiler chamber thereabove, the combination of an external metallic frame extending upwardly alongside the combustion chamber and the boiler chamber, a combustion chamber wall comprising a refractory wall sectionally supported on the frame along the combustion chamber and spaced from the frame and a sheathing wall supported on the frame in collaterally spaced association with the refractory wall, a boiler chamber wall of approximately the thickness of said refractory wall sectionally supported on the frame along the boiler chamber and off-set outwardly from said refractory combustion chamber wall, and a wall portion conjoined with the bottom of the boiler chamber wall and the top of the refractory wall.

8. In a furnace installation, a wall structure as specified in claim 7 and wherein the boiler chamber wall and the combustion chamber wall comprise refractories which are movable relative to one another, and means are provided for anchoring the refractories against displacement from the frame while permitting their relative mobility for accommodation of thermal expansion and contraction.

9. In a furnace installation which affords a boiier chamber disposed over a combustion chamber, a wall structure comprising, in combination, an external metallic frame having supporting members extending upwardly alongside the combustion chamber and boiler chamber, a refractory combustion chamber wall portion supported on the lower portion of said supporting members, a refractory boiler chamber wall portion supported on upper portions of said supporting members above the combustion chamber wall portion and spaced from the upper terminus thereof, said combustion chamber wall and said boiler chamber wall being each made up of sections supported independently one above another and spaced laterally from the frame, means anchoring said sections against displacement toward and from the frame but permitting them to expand upwardly, said combustion chamber wall portion being spaced from the frame a greater distance than the boiler chamber wall portion, and a corbelled refractory wall portion supported on the frame in adjoining association with said combustion chamber and boiler chamber wall portions and independently of the wall portions subjacent and superjacent to it.

10. A boiler furnace structure comprising, in combination, an external metallic frame, a combustion chamber wall supported on said frame and comprising a refractory wall portion spaced inwardly from the frame and a sheathing wall portion spaced outwardly from the refractory wall portion to afford an intervening air passage, a boiler chamber wall supported on the frame above the combustion chamber wall, brackets supported on the frame and disposed intermediate the boiler chamber wall and combustion chamber wall, and an off-set wall portion carried on said brackets with its lower portion in adjoining association with said refractory wall portion and its upper portion in adjoining association with said boiler chamber wall. I

11. In a furnace wall structure, a combination as specified in claim 10 and wherein said off-set wall portion extends over said air passage of the combustion chamber wall.

12. A furnace wall structure comprising, in combination, an external frame, brackets supported thereon at different elevations and extending laterally therefrom, refractories supported on said brackets to form wall sections supported independently one above another in adjoining association, said sections comprising refractories lying flatwise and forming the lower portions of the sections and refractories standing on edge and filling the space between the flatlying refractories of adjacent sections, the flatlying refractories being anchored to the brackets and the standing refractories being removable outwardly from the wall independently thereof, and removable means maintaining said standing refractories against removal from the wall.

RAYMOND D. FOLTZ. ROBERT C. DENNY. 

